Frost-free refrigeration appliance

ABSTRACT

A refrigeration appliance, particularly a domestic refrigeration appliance, has a thermally-insulating housing in which at least one first and one second inner chamber are separated from one another by a thermally-insulated wall. The first inner chamber is divided into a storage compartment and an evaporator chamber. A passage in the thermally-insulated wall connects the evaporator chamber to the second inner chamber. At least one closure element for controlling the air exchange is housed, in the passage, between the evaporator chamber and the second inner chamber.

The present invention relates to a refrigeration appliance, particularlya domestic refrigeration appliance, in which at least one first and onesecond inner chamber are separated from one another by athermally-insulating wall, in a thermally-insulating housing, in orderto form compartments for the storage of refrigerated goods at differenttemperatures, and in which the first inner chamber is divided into astorage compartment for the refrigerated goods and an evaporatorchamber, and a passage in the thermally-insulating wall connects theevaporator chamber to the second inner chamber in order to permit acooling of the second inner chamber without this requiring a separateevaporator.

Generally, in such a refrigeration appliance the second inner chamber isalso divided into a storage compartment for refrigerated goods and anair channel, the passage opening therein and the cold air beingdistributed therefrom in the storage compartment of the second innerchamber via a plurality of openings of an air channel cover.

In order to be able to control the distribution of cold air to the twostorage compartments, a closure element is required, it being possiblethereby to cut off one of the storage compartments from the cold airsupply or to throttle at least significantly the inflow of cold air tothe relevant storage compartment.

In a conventional refrigeration appliance, such a closure elementcomprises a flap which is arranged in a lower region of the air channelof the second inner chamber. With this construction, a lower part of theair channel below the closure element is continuously connected to theevaporator chamber and, therefore, may reach temperatures which may beconsiderably below the desired temperature of the storage compartment ofthe second inner chamber. When this storage compartment, for example, isa normal refrigeration compartment but the evaporator is also designedat the same time to be able to cool a freezer compartment, this lowerregion of the air channel may then be cooled to considerably below 0° C.and lead to frost damage to refrigerated goods in the storagecompartment of the second inner chamber. In order to eliminate this,firstly it is necessary to configure the air channel cover to bethermally-insulating, wherein the space required for athermally-insulating layer at this point is lost from the usable volumeof the second inner chamber, and secondly a reliable seal between theair channel and the storage compartment of the second inner chamber isnecessary in order to prevent an undesirable escape of cold air into thestorage compartment past the closure element, which makes theinstallation of the air channel cover complex and costly.

It is the object of the present invention to provide a refrigerationappliance of the type mentioned in the introduction which is able to bemounted in a simple and cost-effective manner and which has a largeusable volume with the given external dimensions.

The object is achieved, in a refrigeration appliance in which at leastone first and one second inner chamber are separated from one another bya thermally-insulating wall, in a thermally-insulating housing, and thefirst inner chamber is divided into a storage compartment and anevaporator chamber and a passage in the thermally-insulating wallconnects the evaporator chamber to the second inner chamber, by at leastone closure element for controlling the air exchange being housed, insaid passage, between the evaporator chamber and the second innerchamber.

This construction ensures that a boundary between the temperature zonesof the first and the second inner chamber extends exactly inside thethermally-insulating wall. As a result, the need to provide furthercostly thermal insulation inside one of the inner chambers is dispensedwith, and the spaced saved thereby benefits the usable volume. Sinceonly low temperature gradients are present on those parts which areinstalled in one of the two inner chambers, however, a costly seal is nolonger necessary on said parts in order to prevent an undesired flow ofheat, and if a seal is desired it is able to be implemented accurately.

The closure element may comprise a flap which is rotatable between anopen position and a closed position about an axis.

In order to facilitate the installation and for an effective sealingaction of the flap in the closed position, it is advantageous if theclosure element also comprises a frame which completely surrounds theflap in its closed position. This frame may function as a sealing frame.

In this case, the second inner chamber is also preferably divided by anair channel cover into a storage compartment and at least one airchannel in order to facilitate a uniform distribution of the suppliedcold air in the entire storage compartment.

Preferably, two parallel air channels are provided, one thereofextending from the passage into a lower region of the second innerchamber and the other thereof extending from the passage past the lowerregion into an upper region of the second inner chamber.

In order to be able to control a temperature gradient between the upperand the lower region of the second inner chamber, and thus, for example,to be able to use a region of the storage compartment thereof as anormal refrigeration compartment and a further region thereof as a freshfood refrigeration compartment, a closure element is preferably assignedto each air channel. In this case, a single closure element may beassigned to each air channel but also a single closure element maycontrol a plurality of air channels.

For facilitating the assembly, the closure element and/or the closureelements are preferably combined with a motor which drives said elementsto form a sub-assembly which is mounted in the passage between the innerchambers. In this case, a single motor may be assigned to both closureelements and connected to the closure elements via a gear mechanism, forexample by means of two eccentric cams which are arranged in order toinitiate phase-shifted movements of the closure elements, so that atleast a position of the motor in which both closure elements are closed,a position in which the first closure element is open and the secondclosure element is closed, and a position in which the first closureelement is closed and the second closure element is open, and possibly aposition in which both closure elements are open, are present.

One and the same closure element may also block the passage between thefirst and the second inner chamber in a first position, connect thefirst inner chamber to a first air channel of the second inner chamberin a second position and connect the first inner chamber to a second airchannel of the second inner chamber in a third position.

If the first inner chamber and the second inner chamber in each case aredefined by an internal container—typically deep-drawn from a flatplastics material—a tubular housing may be provided in the passagebetween said inner chambers, said housing extending between opposingapertures of the internal containers through a thermally-insulatinglayer of the wall.

The housing preferably comprises two flanges which in each case bearagainst one of the two internal containers. The flanges may bear againstthe sides of the internal containers facing the inner chambers, so thatthe internal containers are pressed against the flanges, when the wallbetween said internal containers is foamed; preferably the flanges bearon the foam side against the internal container.

In order to permit the production of the housing using simple tools, thehousing may be made up of two housing parts, each thereof comprising oneof the flanges.

A foamed part, for example a molded part made of expanded polystyrene,may be arranged between a rear face of the air channel and a rear wallof the internal container of the second inner chamber. Since such afoamed part contributes to the thermal insulation of the second innerchamber, the thickness of the thermally-insulating layer outside theinternal container on the rear wall thereof may be correspondinglyreduced and/or the depth of the internal container may be increased.This in turn permits the aperture of the second inner chamber, where thepassage opens into the first inner chamber, to be positioned outside arounded transition between the bottom and the rear wall of the internalcontainer, whereby the aperture is able to be molded more easily,without usable volume in the second inner chamber being lost thereby.

The air channel cover may come into contact with the foamed part on bothsides of the air channel, so that said foamed part is fixed between theair channel cover and the rear wall.

The closure element should be able to be inserted through one of theapertures of the two internal containers into the housing. At itssimplest, the mounting of the closure element is generally via the upperaperture.

A clamp which secures the closure element in its installed position maybe latched to the walls of the passage between the closure element andthe inner chamber, the closure element being inserted from said innerchamber.

If the closure element and the motor which drives said closure elementare combined to form a sub-assembly, then the clamp is preferablyarranged so as to be placed across the motor, since whilst the clamp isable to secure the sub-assembly effectively at that point, at the sametime it does not obstruct an air flow passing the closure element.

Further features and advantages of the invention are disclosed from thefollowing description of exemplary embodiments with reference to theaccompanying figures, in which:

FIG. 1 shows a schematic section in the vertical direction through thebody of a refrigeration appliance according to the invention;

FIG. 2 shows a section in the horizontal direction along the plane II-IIof FIG. 1;

FIG. 3 shows an exploded view of a housing which is arranged in apassage between the compartments of the refrigeration appliance body ofFIG. 1 and a sub-assembly to be mounted in the housing;

FIG. 4 shows a schematic section through the housing and thesub-assembly in the state mounted in the body of the refrigerationappliance; and

FIG. 5 shows a simplified modification of the housing and thesub-assembly.

FIG. 1 shows a schematic vertical section through the body of a no-frostrefrigeration appliance according to the invention. Two inner chambers2, 3 are formed in the body 1, one 2 in the upper part of the body andthe other 3 in the lower part of the body 1. In a manner known per se,the inner chambers 2, 3 are defined in each case by an internalcontainer 4 and/or 5 which is deep-drawn from flat plastics material.Both internal containers may be deep-drawn in one piece from the sameblank; in the case shown in the figure, the internal containers 4, 5 areproduced separately and encased in profiles of a frame 6 on the frontface of the body 1. An intermediate space between the outer faces of theinternal containers 4, 5 and an outer skin of the body 1, not shown inFIG. 1, is filled with an insulating material layer 7 which is obtainedby injection-molding and expanding a foam-forming synthetic resin in theintermediate space. The insulating material layer 7 extends in this casein one piece into a wall 8 between the inner chambers 2, 3.

The inner chamber 3 is sub-divided by a partition 10 substantiallyparallel to the rear wall 9 of its internal container 5 into a storagecompartment for refrigerated goods, in this case a freezer compartment11 and an evaporator chamber 12. A further wall 13 divides theevaporator chamber 12 into a suction region 14 in which a lamella-typeevaporator 15 is also located and a distributer region 16. A fan 17 isarranged in an opening of the wall 13 in order to suction air throughthe evaporator 15 and to pump the air thus cooled into the distributorregion 16. Via distributor openings 18 in the wall 13, a portion of thecooled air passes directly back into the storage chamber 11. Theremaining air passes via a passage 19 in the wall 8 into an air channel20 of the upper inner chamber 2.

The air channel 20 is defined toward a rear wall 23 of the internalcontainer 4 by a molded part 24 made of expanded polystyrene (EPS) anddelimited from a storage compartment 21 by a plate-shaped air channelcover 22. The air channel cover 22, and the wall 13, are provided withdistributor openings 18, via which the cold air distributed verticallyis able to escape into the storage compartment 21.

The air channel 20 and the air channel cover 22 may extend over theentire height of the inner chamber 2; in the design shown here theyextend only from the bottom 25 of the inner chamber 2 to a horizontalpartition 26 inserted in the internal container 4, so that the airguided in the air channel 20 is only able to be distributed in a lowerregion 27 of the storage compartment 21. In order to supply a region 28above the partition 26, a second air channel 29 is guided through themolded part 24 partially outside the cutting plane of FIG. 1 and the aircirculating in this air channel 29 is distributed in the upper region 28of the inner chamber 2 via distributor openings 18 of a further airchannel cover 30.

FIG. 2 shows a section through the lower region of the normalrefrigeration compartment 2, level with the line II-II of FIG. 1. Thecutting plane of FIG. 1 is denoted in FIG. 2 by I-I. The air channel 20in this case is defined at the front by the air channel cover 22 andtoward the rear wall 23 and, in the lateral direction through the moldedpart 24, the air channel cover 22 bears against the molded part 24 onboth sides of the air channel 20.

Latching connections are provided in order to fix the air channel cover22 in the position shown and to hold the molded part 24 clamped betweenthe air channel cover 22 and the rear wall 23. Here, the latchingconnections in each case comprise a sleeve 31 and a latching pin 32engaging in the sleeve. The sleeve 31 is bonded, welded or fastened inanother suitable manner to the rear wall 23 and engages in a passage 33of the molded part 24. The latching pin 32 has a shank 34 with aplurality of frusto-conical segments which, when inserted into thesleeve 31, which is slotted in the longitudinal direction, widen saidsleeve in a resilient manner until the segments come into engagementwith complementary latching contours in the interior of the sleeve 31.Each latching pin 32 is inserted sufficiently deeply into its sleeve 31until a head 35 of the latching pin 32 bears fixedly against the airchannel cover 22.

In each case at both ends of the passage 19 apertures 37 (see FIG. 1)are cut into the bottom 25 of the internal container 4 and the top 36 ofthe internal container 5. A housing 38 which extends between theapertures 37 through the wall 8, in order to prevent the passage 19 frombeing closed when the insulating material is foamed, is shown in FIG. 3in a detailed perspective view. The housing 38 comprises a lower housingpart 39 and an upper housing part 40 which are injection-molded fromplastics separately from one another and plugged together beforeinserting into the wall 8.

The lower housing part 39 in this case comprises two pipe connectors 41,42 which are slightly widened in the upward direction and arerespectively of rectangular cross section and a flange 43 extendingaround the lower ends of the pipe connectors 41, 42, said flange beingprovided in order to bear against the top 36, all around the aperture 37thereof, when the housing 38 is inserted from the rear face of the body1 into the wall 8. On its lower face, not visible in FIG. 3, the flange43 may be provided with flat ribs which engage in the aperture 37 of thetop 36 along the edges thereof in order to fix the installed position ofthe housing 38 in an accurate manner.

In the upper housing part 40 a flange 44 surrounds an individualconnector 45 which is also rectangular in cross section and which at itslower end branches into two connecting parts 46, 47 complementary to thepipe connectors 41, 42. On the narrow sides of the flange twoprojections 67 are formed which together with the flange form grooveswhich are open in the lateral direction. The aperture 37 of the bottom25 at its edge facing the rear wall 9 has two widenings 68 (see FIG. 4),the projections 67 passing through said widenings when inserting thehousing 38 into the wall 8, so that in the mounted state they bearagainst the bottom 25 and clamp the housing 38 to the bottom 25.

When the body 1 is foamed, retaining tools are inserted into the innerchambers 2, 3, said tools forcing the bottom 25 and the top 36sufficiently far apart until both bear against the flanges 44, 43 in afoam-tight manner.

In each case a latching projection 49 is positioned on the narrow sides48 of the connector 45 such that when the downwardly tapering connectingparts 46, 47 engage by a frictional connection in the pipe connectors41, 42, resilient latching hooks 50 of the lower housing part 39 engagebehind the latching projections 49.

A sub-assembly 51 shown in FIG. 3 above the upper housing part 40comprises a motor housing 52 in the form of a vertically orientedcuboid, rectangular frames 53, 54 protruding from the two main surfacesthereof in plan view. The sub-assembly 51 is provided in order to beinserted, in the orientation shown, from above into the upper housingpart 40; in the installed position the motor housing 52 divides theinterior of the connector 45 into two parts, one thereof extending inthe extension of the connecting part 46 and the other thereof extendingin the extension of the connecting part 47, and the frames 53, 54 arepositioned on a shoulder 55 extending on at least one longitudinal wallof the connector 45.

In each frame 53, 54 a flap 56 (see FIG. 4) is pivotably mounted aboutan axis 57. In its closed position the walls of the flap 56 bear tightlyagainst the frame 53 and/or 54 so that each flap 56 is able to block oneof the two passages on both sides of the motor housing 52. From thisclosed position shown as an outline in dashed lines in FIG. 4, each flap56 is pivotable downwardly into the connector 45 until it reaches anopen position illustrated in solid lines in FIG. 4, in which it does notprevent an air flow from the evaporator chamber 12 to one of the airchannels 20 and/or 29.

In addition to an electric motor, a gear mechanism is also accommodatedin the motor housing 52, said gear mechanism making it possible tocontrol the positions of the flaps 56 independently of one another bymeans of two eccentric cams, as mentioned above, for example. Whenrefrigeration is not required in the normal refrigeration compartment 2,both flaps 56 are closed, when refrigeration is only required in thelower region 27 only the flap 56 of the frame 53 is open in order tosubject only the air channel 20 to cold air, when refrigeration isrequired in the upper region 28 only the flap 56 of the frame 54 is openand when refrigeration is required at the same time in both regions 27,28 both flaps 56 may be open at the same time.

Since the upper region 28 and the lower region 27 of the upper storagecompartment 21 are thus selectively able to be subjected to cold air,different temperatures may be set in both regions. The temperature ofthe lower region 27 should be the lower temperature, not least becauseat the height of the lower region 27 the molded part 24 is thicker andthus the thermal insulation of the lower region 27 is more effectivethan that of the upper region. Thus, in particular, the upper region 28may be used as a normal refrigeration compartment and the lower regionmay be used as a fresh food refrigeration compartment.

In a simpler design of the refrigeration appliance, in which the storagecompartment 21 is not sub-divided and only one individual air channel isprovided behind the cover 30, one of the frames 53, 54, the flap mountedtherein and optionally the eccentric cam driving the flap may bedispensed with.

A clamp 58 is also provided in order to fix the sub-assembly 51 in theconnector 45, said clamp in the mounted state extending over the upperface of the motor housing 52 from one longitudinal wall of the connector45 to the other. The clamp 58 has an upper wall 59 and two side walls 60which encompass the motor housing 52 on both sides. In the mountedstate, the clamp 58, on the one hand, is fixed by engagement in a recess61 to a rear longitudinal wall of the connector 45 and, on the otherhand, is fixed by latching between two latching hooks 62 to a front edgeof the flange 44. On the clamp 58, as shown in FIG. 3, a hook 63 may beprovided, a supply cable 64 of the motor being able to be secured belowsaid hook in order to ensure that it does not hang into one of theframes 53, 54 and prevent the movement of the flaps 56.

FIG. 5 shows a simplified variant of the housing 37 and the sub-assembly51 in a schematic section. The sub-assembly 51 in this case comprises amotor located outside the cutting plane and a single flap 56, of abutterfly shape, which is rotatable about an axis 57 perpendicular tothe cutting plane. The sub-assembly is fixed by a clamp 58 extendingperpendicular to the cutting plane, acting on front walls of the upperhousing part 40, and which divides the opening of the upper housing part40 into a front part 65 communicating with the air channel 20 and a rearpart 66 communicating with the air channel 29. In the position of theflap 56 shown in solid lines, only the air channel 20 is subjected tocold air; after a rotation of the flap 56 clockwise by ca. 30°, into theposition shown in dashed lines, the cold air is distributed to both airchannels 20, 29; after a further rotation by ca. 30°, only the airchannel 29 is supplied, and after a further rotation by ca. 60° both airchannels 20, 29 are blocked. All of the positions are accessible duringa continuous rotation, without the rotational direction of the motorhaving to be altered.

LIST OF REFERENCE NUMERALS

-   1 Body-   2 Inner chamber-   3 Inner chamber-   4 Internal container-   5 Internal container-   6 Frame-   7 Insulating material layer-   8 Wall-   9 Rear wall-   10 Partition-   11 Freezer compartment-   12 Evaporator chamber-   13 Wall-   14 Suction region-   15 Lamella-type evaporator-   16 Distributor region-   17 Fan-   18 Distributor opening-   19 Passage-   20 Air channel-   21 Storage compartment-   22 Air channel cover-   23 Rear wall-   24 Molded part-   25 Bottom-   26 Intermediate wall-   27 Lower region-   28 Upper region-   29 Air channel-   30 Air channel cover-   31 Sleeve-   32 Latching pin-   33 Passage-   34 Shank-   35 Head-   36 Top-   37 Aperture-   38 Housing-   39 Lower housing part-   40 Upper housing part-   41 Pipe connector-   42 Pipe connector-   43 Flange-   44 Flange-   45 Connector-   46 Connecting part-   47 Connecting part-   48 Narrow side-   49 Latching projection-   50 Latching hook-   51 Sub-assembly-   52 Motor housing-   53 Frame-   54 Frame-   55 Shoulder-   56 Flap-   57 Axis-   58 Clamp-   59 Upper wall-   60 Side wall-   61 Recess-   62 Latching hook-   63 Hook-   64 Supply cable-   65 Front part-   66 Rear part-   67 Projection-   68 Widening

1-15. (canceled)
 16. A refrigeration appliance, comprising: athermally-insulated housing; a thermally-insulated wall having a passageformed therein; at least one first and one second inner chamber beingseparated from one another by said thermally-insulated wall in saidthermally-insulated housing, said first inner chamber is divided into astorage compartment and an evaporator chamber and said passage in saidthermally-insulated wall connecting said evaporator chamber to saidsecond inner chamber; and at least one closure element for controllingan air exchange is housed, in said passage, between said evaporatorchamber and said second inner chamber.
 17. The refrigeration applianceaccording to claim 16, wherein said closure element has a flap.
 18. Therefrigeration appliance according to claim 17, wherein said closureelement has a frame which completely surrounds said flap in a closedposition.
 19. The refrigeration appliance according to claim 16, furthercomprising an air channel cover, said second inner chamber is divided bysaid air channel cover into a further storage compartment and at leastone air channel.
 20. The refrigeration appliance according to claim 19,wherein said at least one air channel is one of two air channels, afirst of said air channels extends from said passage into a lower regionof said second inner chamber and a second of said air channels extendingfrom said passage past said lower region into an upper region of saidsecond inner chamber.
 21. The refrigeration appliance according to claim20, wherein said at least one closure element is assigned to each ofsaid air channels.
 22. The refrigeration appliance according to claim21, further comprising a motor for driving said at least one closureelement, said at least one closure element combined with said motorforms a sub-assembly which is mounted in said passage.
 23. Therefrigeration appliance according to claim 19, wherein saidthermally-insulated wall has a thermally insulating layer; wherein saidfirst inner chamber and said second inner chamber in each case aredefined by an internal container each having an aperture formed therein;and further comprising a tubular housing and in said passage saidtubular housing extends between said apertures of said internalcontainers through said thermally insulating layer of saidthermally-insulated wall.
 24. The refrigeration appliance according toclaim 23, wherein said tubular housing has two flanges which in eachcase bear against said internal container of one of said first and saidsecond inner chamber.
 25. The refrigeration appliance according to claim24, wherein said tubular housing has two plug-connected housing partseach with one of said two flanges.
 26. The refrigeration applianceaccording to claim 23, further comprising a foamed part disposed betweena rear face of said air channel and a rear wall of said internalcontainer of said second inner chamber.
 27. The refrigeration applianceaccording to claim 26, wherein said air channel cover comes into contactwith said foamed part on both sides of said air channel and said foamedpart is fixed in position between said air channel cover and said rearwall.
 28. The refrigeration appliance according to claim 16, whereinsaid closure element is able to be inserted from sides of one of saidfirst and said second inner chamber into said passage.
 29. Therefrigeration appliance according to claim 28, further comprising aclamp, said closure element is secured by said clamp which is latched tosaid thermally-insulated wall between said closure element and saidsecond inner chamber, said closure element being inserted from saidsecond inner chamber.
 30. The refrigeration appliance according to claim22, further comprising a clamp disposed so as to be positioned acrosssaid motor.
 31. The refrigeration appliance according to claim 16,wherein the refrigeration appliance is a domestic refrigerationappliance.